Z boson production in Pb plus Pb collisions at root S-NN=5.02 TeV measured by the ATLAS experiment


Aaboud M., Aad G., Abbott B., Abdinov O., Abeloos B., Abhayasinghe D. K., ...More

PHYSICS LETTERS B, vol.802, 2020 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 802
  • Publication Date: 2020
  • Doi Number: 10.1018/j.physletb.2020.135262
  • Journal Name: PHYSICS LETTERS B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, INSPEC, zbMATH, Directory of Open Access Journals
  • Istanbul University Affiliated: Yes

Abstract

The production yield of Z bosons is measured in the electron and muon decay channels in Pb+Pb collisions at /S-NN = 5.02 TeV with the ATLAS detector. Data from the 2015 LHC run corresponding to an integrated luminosity of 0.49 nb(-1) are used for the analysis. The Z boson yield, normalised by the total number of minimum-bias events and the mean nuclear thickness function, is measured as a function of dilepton rapidity and event centrality. The measurements in Pb+Pb collisions are compared with similar measurements made in proton-proton collisions at the same centre-of-mass energy. The nuclear modification factor is found to be consistent with unity for all centrality intervals. The results are compared with theoretical predictions obtained at next-to-leading order using nucleon and nuclear parton distribution functions. The normalised Z boson yields in Pb+Pb collisions lie 1-3a above the predictions. The nuclear modification factor measured as a function of rapidity agrees with unity and is consistent with a next-to-leading-order QCD calculation including the isospin effect. (C) 2020 The Author(s). Published by Elsevier B.V.